Electric switch



Junelz, 1928. y 1,673,385 W. WURDACK' ELECTRIC SWITCH Filed Nov. 2, 1925li'atentetll June 12, A1928. p.

UNITED STATES v1,673,385 'PA'rsN'rl OFFICE.

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application med mnmbr This invention relates generally to electricswitches. More particularly, my lnyentlon relates to a certain new anduseful improvement in electric switches ofthe so-called knife typeand-has for its chief object the provision ofl a switch of the typestated which is of inexpensive, compact, and durable form and'structure, and which 1s sov .constructed to effect in an eiiicientmanner lo ielding retention of the blade or blades 1n both neutral andswung or circuit-closing positions.

- And with the above and other ob]ects 1n view, my invention resides inthe novel features of form, construction, arrangement,

and combination of parts hereinafter described and pointed out in theclaims.

In the accompanying drawing,

Figure 1 is a side elevational view of an 2o electric knife-switchembodying my invention, the blades of the switch eing shown in fulllines in neutral position and in dotv and-dash lines in swung or thrown,circuit-u closing position; l

Figure 2 is an end view of the sw1tch; and

Figure 3 is an enlarged vertical or longitudinal sectional view of theswitch, showing the contact-engaging blades in thrown circuit-closingposition opposite to that of Figure 1.

Referring now more in detail and' by reference characters to thedrawing, which illustrates a practical embodiment of my invention, Aindicates a suitable preferably insulation base, rigidly fixedy to whichis a standard or supportpreferably, as shown, in the form of a U-shaped.member B, whose legs 1-1 are presented upwardly and suitabl spaced.

ormed in the upper ends of theY standard-legs 1, are arcuatebearing-recesses. as at 2, for a shaft 3. Fixed upon shaft 3intermediate the standard-legs 1, is a member or block 4 of hexagonal orother suitable polygonal formation; and disposed on shaft 3 outwardly ofthe standard-legs 1, are retaining-nuts 5-5. f

C designates a U-shaped member or yoke which depends from the shaft 3for shiftable movement bodily intermediate the standard-legs 1, the yokeC adjacent the upper ends of its legs 6, 6, being formed withshaft-accommodating apertures 7, whose upper wall is correspondlnglypolygonl' in formatwn, as shown, for inters, im.' semi no. casos.

engaging cooperation with the polygonal block 4, for urposes shortlyappearing. Suitably vrigid attached, as at 8, to the base or bight of,standard B, is a screw-bolt or the like 9, which projects upwardlythrough the bight 10 ofV yoke C, as shown, and dlsposed on bolt 9intermediate its head and the yoke-bight 10, is a coiled spring Fixedyon shaft 3, is a small plate 13 pro-v vided with a laterally presentedfinger 13' working in and adapted for engagement with the end-walls ofan arcuate slot 14 formed in the adjacent wall or leg 1 of standard B,also for purposes shortly appearmg.

Also suitably fixed on the opposite ends of shaft 3, areinsulation-blocks 15, 15, carrying downwardly presented substantiallyyoke-shaped .blade-providing members 16, whose blades 17, 17, arepreferably of the spring-jaw type for electrical engagement withcircuit-contacts or terminals of the knife-type suitably fixed to andupstanding from base A. The switch here specifically illustrated is ofthe so-called double-pole, double throw type, and there are consequentlythree sets of the circuit terminals,

Jas at 18, 19, and 20, suitably located upon the -base A for engagementby the blades 17 as thew shaft 3 is rotarily actuated in one or .theother direction by means of a suitable handle 21 iiXed thereto.

Now, in use and operation, the switchhandle 21 and blades 17 are, Imight say, normally in neutral position or in the osition thereofillustrated in full lines in igure 1, the yoke C being in fulldownwardlypulled position under the tension of spring 12 and the polygonal block 4being in full matching registration or engagement with the polygonallyshaped walls of the yoke apertures 7. It being understood that thespring or other resilient member 12 is constantly resiliently pullingdownwardly upon the yoke C, it will be seen that the engagement betweenthe block 4 and yoke C will retard axial or rotar actuation or movementof the shaft 3 an that the blades 17 will hence be yieldingly retainedin such neutral position. Yet, as the handle 21 is positively swung tothe left, reference being had to Figure 3, to enga e the blades 17 with,and close the circult etween, the terminals 18 and 20, the block 4camwise engages at lll .of slot '14', limiting the swun its corner 22with the ad'acent oblique faces v movement of the switch-bla es 17. The

A spring-pulled yokeC then functions in like manner to retard returningaxial or rotary movement of the shaft y3, the blades 17 being therebyyieldingly retained in such circuitclosing or electrical engagement withsaid terminals. To break the circuit and return the blades 17 to neutralposition, the handle 21 is reversely manually or otherwise forciblymoved to the right, whereupon the block surface or corner 22 rides downthe oblique faces 23 of the yoke apertures 7 and the block 4 and yoke Cassume in due course their full matching registration, the springpulledyoke C functioning then, as described, toTetain the parts in normalposition. Or, should it be desired to engage the blades 17 with, andclose the circuit between, the terminals 18 and 19, the handle 21 isfurther moved to the right, when in a similar manner, the block 4' atits corner 24 rides up, so to speak, the adjacent oblique faces 25 ofthe yoke-apertures 7 and thereby shifts the yoke C upwardly against thepull of its spring 12, the yoke C, following electrical engagementbetween the blades 17 and said terminals 18, 19, functioning tosimilarly retain the blades 17 in electrical engagement therewith, thelinger 13', also in a similar manner, engaging the opposite end wall ofthe slot 14 and limiting the swung movement of the handle 21 and blades17 in such direction.

My new switch comprises few, readily assembled parts, and by itsconstruction the blades are in a simple, but most eiiicient manner,yieldingly retained either in neutral position or in either of theirswung circuit-` closing positions.-

Although not here specifically shown, it will be evident that, bysuitably reducing the length of the slot 14, the switch here illustratedmay be readily converted into one of double-pole, single throw type,that by omitting upon one side of the shaft 3 one of the knife-bladeproviding members 16, the switch here illustrated may be likewise easilyconverted into one of the single pole, double throw type, and that otherchanges in the form, construction, arrangement, and combination of theseveral parts ofthe switchmay be made and substituted for those herein4shown and described without departing from the nature and principle ofmy invention.

Having thus described my invention, what I claim ent is:

1. In an electric switch, an axially movable shaft, a block cam fixed onthe shaftz a shiftable cam member adapted for camwise mterengagingco-operation with said block, and means resiliently pulling upon saidmember for yieldingly retarding through the engagement between saidmember and said block axial movement of the shaft. l

2. In an electric switch, an axially movable shaft, a polygonally-shapedblock lixed on the shaft, a member depending from the shaft and havingpolygonally shaped apertures for camwise -interengaging shiftableco-operation with said block, yand means resiliently pulling upon saidmember for yieldingly retarding through the camwise engagement betweensaid member and said block axial movement of the shaft. l

3. In an electric switch, an axially. movable shaft, apolygonally-shaped block fixed on the shaft, a member depending from theand desire to secure by Letters Patshaft and having polygonally shapedapers ently pulling Aupon said member for yieldingly retarding throughthe Vcamwise engagement between said member and said block axialmovement of the shaft, and means for limiting the axial movement of theshaft. y

4. In an electric switch, a standard having an arcuate slot, a shaftmounted for axial movement on the standard, a contact-engagin bladecarried by the shaft, a polygona ly-shaped block fixed on the shaft, ayokeshaped member depending from the shaft and having polygonally-shapedapertures for camwise interengaging shifting co-operation with saidblock, a member carried by the shaft and working in said slot forlimiting the axial movement of the shaft, and means `resiliently pullingupon the yokeshaped member for retarding through the camwise engagementbetween said member and said block axial movement of the shaft foryieldingly retaining the blade in neutral and swung positions.

In testimony whereof, I have signed my

